Mithrandir Metrics
Player Athletics Refreshed Sep 29 06:00 AM ET
Player profile / Athletics

Jack Perkins

P · Bats/Throws R/R · 6' 1", 220 lb · Age 26

Cards
16
Modules
1
Live Δ
yes
Club Athletics Position P Roster Current MLB team Status Healthy / active roster
Traditional line

Season by season

3D Pitch Lab Projections
WLERAGGSSVIPSOWHIP
2025324.19124338.2371.16
20263136.1037173121.01401.45
2 Seasons6155.6449216159.21771.38
At a glance

Season percentile report

The headline weighs outcome stats (xwOBA, barrels); each bar averages its full strip group below. 100 = best in MLB.

2026-09-29
42
Pitching
percentile
Pitching9 metrics
50
Arsenal6 metrics
66
Rolling projection

Preseason / current pace / Bayesian update

Rolling bands shrink current-season signal toward the preseason prior until the sample earns more weight.

2026-09-29
ERA preseason4.31
ERA current pace5.90
ERA rolling p505.42
Observed weight70%
ERA
4.28 4.82 5.42 6.02 6.56
FIP
3.75 4.12 4.52 4.93 5.30
K%
22.4% 23.5% 24.8% 26.0% 27.1%
BB%
8.0% 8.7% 9.5% 10.2% 10.9%
Live percentile strip

Current traits vs projection tick

100th = best in MLB.

2026-09-29
Pitching · percentile strip
WHIP1.46
27
ERA5.90
12
BB%9.5%
43
K%25.7%
74 +29 vs proj
xwOBA allowed0.311
52 +21 vs proj
Barrel allowed8.6%
32
Fastball velo95.6
70
Hard-hit allowed36.7%
64
Whiff%26.0%
75 -16 vs proj
Mithrandir+

Stuff+ and arsenal context

How nasty this pitcher's stuff grades in our pitch-level model. Missing coverage is shown explicitly.

2026-09-29
Changeup Stuff+104
67
Fastball Stuff+101
40
Mithrandir Stuff+104
71
Slider Stuff+108
92
Cutter Stuff+104
75
Sinker Stuff+102
48
Rolling form chart

xwOBA allowed snapshot line

Live snapshot series; true 50/100 PA windows require PA-level logs

12 snapshots
Mithrandir Metrics ROLLING XWOBA LINE Parameterized Mithrandir chart rendered as SVG for templates and exports. season=2026 Rolling xwOBA allowed Perkins, Jack · Live snapshot series; true 50/100 PA windows require PA-level logs LG AVG 0.313 0.311 2026-09-18: 0.3112026-09-19: 0.3112026-09-20: 0.3112026-09-21: 0.3092026-09-22: 0.3092026-09-23: 0.3092026-09-24: 0.3092026-09-25: 0.3092026-09-26: 0.3092026-09-27: 0.3112026-09-28: 0.3112026-09-29: 0.311 2026-09-18 2026-09-29 xwOBA allowed MITHRANDIR · CHARTS
Optimization map

Arsenal optimization map

Pitch-shape context from this pitcher’s current arsenal snapshot. Hover a pitch to inspect usage, movement, and bat-missing context.

6Pitches 2026Season 30%Top usage
ride armside gloveside +Arsenal gap +Shape contrast
Zone profile

Aggregate zone heatmap

Aggregate zone metrics from seasonal Statcast leaderboards.

Mithrandir Metrics ZONE HEATMAP Parameterized Mithrandir chart rendered as SVG for templates and exports. season=2026 Pitch Zone Profile Perkins, Jack · Aggregate zone metrics; not pitch-by-pitch locations Edge: 36%36%Zone: 46%46%Whiff: 26%26%Called strike: 16%16%First pitch strike: 49%49%Hard hit allowed: 37%37% Dashed border = aggregate mixed-batter zone proxy MITHRANDIR · CHARTS
Pitch arsenal

Usage mix, movement map, and Stuff+ composition

2026 pitch-level arsenal aggregates; current season takes over after 100 tracked pitches across at least 2 pitch types. Descriptive pitch-type Stuff+ composition. Not a promoted predictive metric.

Watch the pitches in 3D →

2026
Mithrandir Metrics PITCH ARSENAL DONUT Parameterized Mithrandir chart rendered as SVG for templates and exports. Pitch Arsenal Perkins, Jack · 2026 arsenal snapshot 4-Seam Fastball: 30.2%Sweeper: 27.9%Changeup: 18.7%Cutter: 15.1%Sinker: 5.4%Slider: 2.7% FF30% · 96 mphprimary pitch FF 30%ST 28%CH 19%FC 15%SI 5%SL 3% MITHRANDIR · CHARTS
Mithrandir Metrics PITCH MOVEMENT Parameterized Mithrandir chart rendered as SVG for templates and exports. Pitch Arsenal Perkins, Jack · 2026 arsenal snapshot 12″24″36″48″ 4-Seam Fastball: 30% usage, 1″ horizontal break, 15″ drop, 95.8 mphFF96 mphSweeper: 28% usage, 0″ horizontal break, 35″ drop, 86.3 mphST86 mphChangeup: 19% usage, 8″ horizontal break, 34″ drop, 89.5 mphCH90 mphCutter: 15% usage, 0″ horizontal break, 24″ drop, 92.7 mphFC93 mphSinker: 5% usage, 7″ horizontal break, 22″ drop, 94.8 mphSI95 mphSlider: 3% usage, 1″ horizontal break, 42″ drop, 85.9 mphSL86 mph less drop ↑ more drop ↓ · horizontal break ↔ · dot size = usage · break incl. gravity MITHRANDIR · CHARTS
PitchUsagePitchesStuff+Status
SL 30.6% 360 108 qualified
FB 30.2% 355 101 qualified
CH 17.3% 203 104 qualified
FC 16.3% 192 104 limited sample
SI 5.5% 65 102 limited sample
Method note

Renamed from the attempted Kirby Index after audit; true Kirby requires release-angle trajectory data.

Reference layer

Current snapshot

Age26
Height6' 1"
Weight220 lb
Debut2025-06-22
Live layer

Delta / regression

ERA Δ+1.25
K% Δ+0.040

positive regression

Regression watch

Unlucky so far. Better days ahead.

2.5σ gap
wOBA-against (actual)0.376
xwOBA-against (deserved)0.311

Perkins’s wOBA-against sits at 0.376, but the quality of contact underneath says it should be 0.311 — a gap of 0.064, 2.5 standard deviations from the MLB norm over 124 IP. The results have been worse than the process deserves; as the sample grows, expect the numbers to climb back toward the underlying level.

Mithrandir coverage

Module shelf

ModuleCardsLatestSignal
Pitching162026-09-26Sweeper played up through ST/FF tunnel quality
Projection links / recent games

Available detail

Pitcher Projections 202621.6% K | 4.65 ERAProjection
2026-04-13 vs TEX4 ER / 4 K1.2 IP